I have the Clifford cam, headers, intake and this afternoon I will fire up the Weber Redline FI kit i just finished the install last night. Their stuff is top shelf and I think to much is made of the single/dual plane intake debate at low RPMs you just are not moving that much air. The same can be said of the exhaust manifold scavenging while technically correct in reality its a inline 6 cylinder and you will have limitations on configuration. and there is alot more to the scavenging debate than just the headers. There is intake and exhuast valve sizing, valve overlap, duration condition of the current exhuast and on and on.

In reality they work better than the stock stuff. Now will you see their numbers? If everything else is perfect timing, fuel with all the other stuff and you are running a 72 degree day with low humidity on a dyno you will. But perfect conditions are hard to come by.

Personally the quality is some of the best i have seen and it will make a nice improvement.

I just installed the Clifford on my 258, it runs great, the weak link is the gasket they give you, I have blown-out two in 700 miles. now I'm in the process of making my own. I found one site that would make the gasket out of 1/8" graphite composite, but the cost is $200.00 for 4 gaskets, that was mainly for the set-up charge. Any ideas out there

I just installed the Clifford on my 258, it runs great, the weak link is the gasket they give you, I have blown-out two in 700 miles. now I'm in the process of making my own. I found one site that would make the gasket out of 1/8" graphite composite, but the cost is $200.00 for 4 gaskets, that was mainly for the set-up charge. Any ideas out there

I blew out my Clifford gasket at 2,000 miles. I replaced it with a Hedman header gasket and it has held up longer than the Clifford and still going strong, plus you get two gaskets when you buy from Hedman. I think the Clifford was just too thick of a gasket to be long-term effective.

Jeeps are sorta like cats, but tend to have more than just nine lives.

If it were me, I'd stay clear of the dual-outlet header. If you merge the two into one, similar to the Doug Thorley Tri-Y headers, then it would probably function pretty well but as a true, dual exhaust I'd be pretty hesitant. Scavenging is important for torque at any rpm and can be optimized with any camshaft/head/intake/underwear color and birthday combo.

Don't buy into the "you need backpressure to build torque" stuff. I just did a Hedman header 6 to 1, 20 inch long 2.5 in collector into 3 in system and it makes way more torque than stock and pulls nicely from 800 rpm in third gear with 34 inch swampers and stock gearing.

Next up for me is recurving the dizzy, Cliffy intake and most likely a Street Demon 2 barrel.

Lawless,
Just curious at why you didn't go with larger Chevy valves like what's listed on Clifford's site - 1.94" intake, 1.50" exhaust?
With the cam size do you still get alot of off idle torque for offroading?
I'm still in the information download on which avenue to venture down, the 4.0L head swap, or play with the stock head. I have a great local machine shop, so I'm undecided.
Later, T.J.

Lawless,
Just curious at why you didn't go with larger Chevy valves like what's listed on Clifford's site - 1.94" intake, 1.50" exhaust?
With the cam size do you still get alot of off idle torque for offroading?
I'm still in the information download on which avenue to venture down, the 4.0L head swap, or play with the stock head. I have a great local machine shop, so I'm undecided.
Later, T.J.

Oddly enough, that's one thing I didn't double check with the machinist when he was working the head. He just said that it already had larger valves in it, and I didn't ask about the size until it was all done. In hindsight, I'd put the Clifford recommended valves in.

The cam is still very responsive and has a lot of torque off idle. If I was just offroading in my Jeep, I'd most adsureadly go with a cam more in a lower rpm range though. Gas mileage isn't that great in the lower ranges of the cam. Since my Jeep is a daily driver, and I wanted it to move down the highway and interstate, I went with a higher rpm cam.

Being a bit old fashioned, I really wanted to make the 258 head work instead of opting for the 4.0 head.

Jeeps are sorta like cats, but tend to have more than just nine lives.

It will be interesting to hear opinions on this. Though I never considered the Howell injection system, I was stink-eyeing the Clifford Weber side draft setup.

I talked to Rob at Howell the other day and they have a prom tuned for this set up, had good things to say about it, though I am sure he is not going to have many if any negative things to say about a product he sells. I will admit he answered my questions and did not act as though I was wasting his time.. Rare to find these days.. I called painless wiring the other day about one of their harnesses, and they guy on the tech line was short with me and seemed bothered that I called to get details on the product, making me think twice about using them, though I should not let his attitude sway me away from a good product, torn here I guess. Just wondering about this set up, hopefully someone will chime in that has used this or a similiar combo..

I did run that combination and it worked well enough. There are some limitations to the Howell TBI kit mostly it has to do with the fuel pressure at 12 PSI it dosent atomize like the higher pressure systems. And cold mornings the fuel will puddle in the manifold till it warms up. So when its cold it stumbles a bit but after that its ok.

If you can run the Weber Redline look into that it blows the doors off the Howell TBI Big Time.

I have a 250 in a 1963 chevy 2 with the clifford intake 390cfm holley dual exhaust and also one of their cams. I don't remember what the lift and duration is on it but all I know is that before I put my posi in it and 4:11 gears I was beaten in the 1/4 mile by a 5.9L dodge dakota by only 1 car length. Don't think that is bad for a little inline 6. The car has been on the road for 14 years and I have had no problems so far. Clifford makes a good product and I am looking into rebuilding my 258 with their parts this time too. Just remember to put the dual valve springs or they will break over time. I broke 2 over the years until I put the better springs in it.